1. Field
Embodiments relate to an oil supply structure of a hermetic reciprocating compressor in which a compression mechanism to compress a refrigerant through reciprocation of a piston and a power transmission mechanism to generate driving force are integrated and accommodated in a hermetic case.
2. Description of the Related Art
In general, a compressor, which is one of the components of a refrigeration cycle apparatus, is designed to compress a refrigerant at high temperature and high pressure. The compressors may be divided into various types depending on the compression technique and the sealing structure. Among other compressors, the hermetic reciprocating compressor includes a compression mechanism to compress the refrigerant through reciprocation of a piston and a power transmission mechanism to drive the compression mechanism, and has the compression mechanism and the power transmission mechanism installed in one hermetic case.
Such a hermetic reciprocating compressor includes a rotating shaft to transmit driving force from the power transmission mechanism to the compression mechanism. Also, a lower portion of the hermetic case retains oil used to lubricate and cool components of each mechanism, and the rotating shaft is provided with an oil supply structure to raise the oil to supply the same to each component.
An example of such a compressor is disclosed in Korean Patent Application Publication No. 10-2005-0052011. According to this document, an inner channel is provided in the lower portion of the rotating shaft to raise the oil, and a spiral groove connected to the inner channel is formed on the outer circumferential surface of the upper portion of the rotating shaft, which is supported by a shaft support of a frame.
The oil retained in the hermetic case configured as above is guided through the inner channel formed in the rotating shaft to the spiral groove formed on the outer circumferential surface of the rotating shaft. When the oil is raised, it lubricates the parts on the outer circumferential surface of the rotating shaft between the rotating shaft and the shaft support.
However, since the oil lubricates the parts between the rotating shaft and the shaft support while being raised, surface pressure of the shaft support applied to the oil may limit the rising speed of the oil, thus limiting reduction in revolutions per minute (RPM) of the rotating shaft.